Pump construction



J. F, EATON March 3, i936.

PUMP CONSTRUCTION Filed March 19, 1954 Patented Mar. 3, 1936 UNITED STATES PUMP CONSTRUCTION John F. Eaton, Tulsa, Okla., assgnor to The Engineering Company, Tulsa, Okla.

Application March 19, 1934, Serial No. l716,381

2 Claims.

The present invention relates to improvements in pumps and in particular to stuffing boxes for use in oil well pumps or the like.

The primary object of the invention is to pro- 5 vide a multiple-type stuing box assembly comprising two or more separate and independent stufling box units arranged in series and each having its own set of packing adapted to be held in place snugly against the pump rod by the fluid column pressure as each successive packing is called upon to function by wear and leakage past the primary box.

A further object in View is to provide an assembly arrangement of the stuing boxes as above-mentioned with intermediate spacing members forming a lubricant means embodying a retaining chamber in which both a lubricant and a suitable medium may be introduced for maintaining the surfaces of the pump rod or tube lubricated and smoothed and free from pits caused by the corrosive action of the well iiuids or other- Wise.

Other and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof dened by the appended claims.

In the drawing:-

Fig. 1 is a longitudinal sectional view of an embodiment of this invention, and

Figs. 2 and 3 are enlarged sectional views thereof.

Like reference characters designate corresponding parts in the several figures of the drawing.

Referring to the drawing, the stufng box invention is shown as applied to an oil well pump of the inserted type, having a stationary working barrel and travelling plunger tube. This type of pump is run on the end of the sucker rods inside the tubing to the bottom of the well, where a cup hold-down, or mechanical hold-down, attached to the lower end of the pump, and not shown in the drawing, holds the working barrel of the pump stationary inside of the tubing,

provides a fluid seal between the pump and the tubing, and thus allows the plunger tube to move with the sucker rods. It will be understood that only that section of the pump device in which the stuiiing box units are interposed is shown,

the upper and lower portions being of conventional form and construction and not claimed herein as a part of this invention. l designates the upper extension tube of the pump in which the rod 2 is disposed, said rod having connected thereto the upper travelling valve cage 3. Be-

(Cl. 10S-202) neath this is the upper travelling valve seat retainer 4. To the lower end of the travelling valve seat retainer 4 is attached the upper end of the hollow plunger tube 6. Fluid is admitted to the lower end of the plunger tube 6 on the down- 5 stroke, and is discharged through ports 3 in the travelling valve cage 3. The fluid then passes into the space 5 in the extension tube I, and is thence discharged from the pump into the tubing above the pump. There is suiiicient clearance 10 between travelling valve cage 3 and the inner wall of the extension tube I to permit passage of fluid. To the lower end of the tube I is connected the upper bushing housing 1 having an internal shoulder 1' on which is seated the upper bush- 15 ing 8 which is adapted to be held in place by means of the bushing retainer ring 9 which has threaded connection with the extension tube, as clearly shown in Fig. 2 of the drawing. This bushing 8 provides a bearing surface for the mov- 20 ing plunger tube in the operation of the pump. Its housing is not screwed down on the packing of the adjacent stuffing box. Externally, the bushing housing is formed with a wrench square to facilitate assembly in the usual manner. 25I

To the housing 1 is connected the upper stuffing box and bushing housing unit I0 containing the packing II of conventional type and the packing follower I2 seated thereon. In the lower end of the stuliing box unit is mounted the bushing I3. 30 It will be apparent that as many of these stuffing box units as desired may be incorporated in line, but in the drawing there are shown only two of 1 such units, the second one being designated generally by the reference character I4 and this unit 35 need not be further described in detail since it corresponds to the one above set forth.

At 20 is shown the upper seating ring for the working barrel 2 I, which is provided at its lower extremity with the usual standing valve and 40 cup hold-down which are not shown as they form no part of this invention.

Between the stuffing box units referred to there is preferably interposed what I term for the purpose of this description a lubricator unit or sec- 45 tion which is composed preferably of the adaptor part I5 having threaded connection with the lower end of the upper stuiling box and the barrel I6, The internal diameter of this barrel is sufficiently larger than the plunger tube 6 to 50 form a chamber I1 surrounding the tube and in which a lubricant may be introduced through a suitable opening I8 in the wall of the adaptor, closed by the screw plug I9.

Into the chamber I1, I also propose to introduce 55 a corrosion protective substance which will tend to keep the surface of the pump rod or tube smooth and free from pits caused by the corrosive action of the well fluids on the metal as hereinbefore premised. The substance used will be such that it will adhere to the surface cracks and grains of the metal, or minute surface irregularities, of which there are many on even the smoothest machined surfaces, providing a thin film over the surface of the metal which will be constantly renewed at each stroke of the pump. Also, after the surface of the tube has corroded slightly, the surface will be roughened, and will have more and deeper surface cracks and pits, which cracks and pits are known to be the critical points .at which further corrosion takes place. The substance used in the lubricator will fill these cracks and pits, and will remain in them Yor be constantly replaced at each stroke of the pump, thus retarding or preventing further corrosion at these points, lsince the well fluid will not enter the cracks. Because the substance will be in the cracks or pits, it will be below the rubbing surface of the tube, :and will not lbe removed by passing through the stuffing box :packing rduring op- Y eration, The substance used will preferably tend to glaze the surface `of the rod and will not be wiped off by passage through the stuffing box packing, said lpacking .becoming partly impregnated with the substances filling the surface irregularities thoroughly as the rod passes through. For the purpose there may be used a mixture of liquid wax or heavy oil or grease, if the particular substance chosen is to have no chemical action or reaction. Also, it is intended or proposed to use softer metals, such as zinc, copper, or lead filings, or mercury in the chamber l1, as it is known tha-t these metals, being softer than steel, become imbedded in the surface irregularities of steel when runder pressure, and thus will ll corrosion pit-s and cracks, preventing corrosive well fiuids from reaching these critical points, as explained above, and making the surface of the plunger tube smoother, thus reducing friction and packing wear. Corrosion protection using oils,

greases, waxes, or softerrretals as described above I term physical protection, as no use is made of chemical action or reaction.

I do not wish, however, to be confined to a corrosion protection of strictly physical nature as equally desirable results may be obtained by employing a vsubstance which would react chemically with the well fluids. I may make use of a type of corrosion protection of both a `chemical and physical character as follows: I may use zinc or aluminumV in the chamber I1, which metals, being more active chemically than theiron in steel, will react more readily with the corrosive agents inthe well fluid, and also, being softer than steel, will become imbedded in the surface irregularities, cracks and pits in the steel plunger tube, as above described. The zinc or aluminum, being imbedded in the surface of the steel plunger tube, will be exposed to the well fluids, and will react chemically with the acids, alkalies or salts present in the well fluids to form oxides, sulphides, chlorides, etc., of zincror aluminum. YThese oxides, sulphides, having been chemically formed, will form a coat over the surface of the plunger, and filling the pits and cracks thereof, and will then protect the plunger tube physically, as follows.Y This type of protection occurs when the bright surface of zinc or aluminum is exposed to the atmosphere. The ,pure Zinc or aluminum at the surface oxidizes in air to form zinc or aluminum oxide, which oxides form a perfect coating over the pure metal beneath preventing further oxidation of the metal. Such use of this type of protection is within the purview of my invention.

In the functioning of the construction above described, it will be obvious that the upper packing, that in the top stuiiing box, will be compressed by the weight of the fluid column which will keep the packing in its place at all times and prevent leakage. This fluid load at times is known to reach as high as three thousand pounds per square inch and is sufficient to maintain the necessary pressure to provide a leak-proof joint. In the course of time, under the conditions, wear of the packing will take place, allowing the fluid to pass by, whereupon the next stuing box becomes effective. Thus a long maintenance of the joint may be obtained by the use of a plurality of these stuffing boxes, only one of which may be in service or subject to wear at a time. This particular arrangement and operation constitutes an important improvement in pump constructions, materially reducing the necessity to pull and repair or repack the pumps, especially if in conjunction with these stuffing boxes the intermediate lubricating Yand corrosion protecting chamber unit is employed. Prolonged and uninterrupted operation of a pump is an objective highly sought for in oil well operations and the assembly arrangement which is hereinbefore set forth is believed to be highly effective for accomplishngthe desired result. Y

It will be understoodV that I do not wish to be .restricted to the use of this stuffing box arrangement in oil well pumps Y as it may readily be adapted to other instrumentalities having relatively movable parts, nor to the details of construction herein shown, as changes may be made therein without departing from the spirit of the invention and within the scope of the claims hereand a plunger, of a plurality of independent stuffy ing box units arranged in the tube line and each comprising a tubular body screw threaded at both ends and having a packing chamber extending the major portion of its length of substantially larger diameter than the plunger and terminating at its lower end in a packing seat, compressible packing in said chamber, a movable packing follower at the top of the chamber seated on the packing and subject to the uid pressurein said tube above the unit to compress the packing in the chamber, the lower end of the unit having therein a rod bushing seated beneath and against the packing seat and adapted to be held seated therein by the end of the nextY succeeding unit of the tube, the upper of said stuffing box units being threadably connected to the tube and the lower stuffing box unit being threadably connected to the barrel and means threadably connectingthe stuflingbox units together, said plunger passing through the stuffing boxes and rod bushings and each stuffing box beingv adapted to sustain the fiuid pressure in the tube until substantially worn.

2. In a pump construction of the class described, the combination with a tube, a barrel, and a plunger, of a plurality of independent stuffing box units arranged in the tube line and each comprising a tubular body screw threaded at both ends and having a packing chamber extending the major portion of its length of substantially larger diameter than the plunger and terminating at its lower end in a packing seat, compressible packing in said chamber, a movable packing follower at the top of the chamber seated on the packing and subject to the fluid pressure in said tube above the unit to compress the packing in the chamber, the lower: end of the unit having therein a rod bushing seated beneath and against the packing seat and adapted to be held seated therein by the end of the next succeeding unit of the tube, said plunger passing through the stuiiing box units and rod bushings, the top stuifing box unit being threadably connected to the tube and the lowermost unit being threadably connected to the barrel, each stuflng box being adapted to sustain the fluid pressure in the tube until substantially worn, and a lubricant holding unit interposed between the stuffing box units aforesaid and threadably connected thereto and comprising a tubular body formed with a lubricant chamber surrounding the plunger, said unit including an adapter section removably connected to the top of the unit and having a supply opening therein to enable introduction of the lubricant into the chamber surrounding the plunger. 

